Well casing fill-up device



Aug. 12, 195s J W. MALY ETAL WELL CASING F] ILLUP DEVICE Filed Nov. 14,1955 ATTRNE X United States Patent O WELL CASING FILL-UP DEVICE Joe W.Maly and James C. St. John, Duncan, Okla., assignors to Halliburton OilWell Cementing Company, Duncan, Okla.

Application November 14, 1955, Serial No. 546,620

2 Claims. (Cl. 166-224) This invention relates generally to well casingattachments and moreparticularly to an improved device suitable forlling a well casing that is being lowered into a well bore.

A 4well casing that is to be lowered into a well bore and cementedtherein is ordinarily vequipped with a oat shoe or collar at its lowerend. An upwardly closing check valve, as usually provided in suchfloating equipment, prevents fluid passage into the well casing.Advantages found in these devices are prevention of blow outs, provisionfor buoyancy `of the casing string, and retention of the placed cementuntil setting occurs.

When a well casing has been lowered to its final position, cement Iispumped down through the casing, out through the check valve and thenceinto the well bore about the casing. The subsequent setting of thiscement bonds the casing to the surrounding formation.

As is well known, the casing may be and usually is overly buoyant whenlowered entirely empty. In response to such an undesirable condition acommon practice is to partially ll the casing with uids as said casingis being assembled and lowered into a well bore. Such lling is usuallyperformed manually by the drilling crew and requires considerable extratime and elort. Various well casing attachments have been devised tohave this lilling operation performed as needed and without elort on thepart of the crew. The most common of such attachments are devicesincorporated into the previously mentioned oat shoes. such devices havebeen only partially solved. One of such problems is that, as eachsection of casing is added, the somewhat abrupt drop of the casingstring causes a high impact pressure or -ramming elect at the guide shoeand results in overlling and overow of the casing. Another such problemis that cuttings and other detritus suspended in the drilling fluidssometimes wedge or block such devices.

It is therefore the general object of this invention to provide atill-up device for well casings which will have reliable means for thecontrolled lilling of a casing string with well uids, positive means ofretaining such fluids within the casing, permanent means for preventingfurther lling of the casing with well fluids when at its nal position,and means for providing a full flow opening through the device at suchtime as cementing operations are to be performed.

In accordance with the present invention an improved well casing ll-upmeans is provided having in combination a tubular body having a passagetherethrough and at least one transverse port through the walls thereof,with a sleeve-like member mounted within said body and adapted to bemoved longitudinally to a rst and second position therein. The sleevehas at least one transverse port therein which is adapted to be inregistry with said body port only when said sleeve is in said firstposition. Said sleeve port has check valving means responsive to apredetermined dilerential pressure created across said Problemsconfronting ice registered ports from outside the body. Said sleeve alsohas a yieldable closure member responsive to pressure through said body.A yieldable means is provided for supporting said sleeve in said rstposition against pressure applied through said body. Means for latchingsaid sleeve-in said second position is provided, the arrangement beingsuch that pressure applied through said body and to said sleeve memberovercomes said yieldable sleeve support and moves said sleeve from saidrst to said second position and a higher pressure through said bodyovercomes said sleeve closure member, thus providing a full openingthrough said sleeve.

Other objects and advantages reside in certain novel features ofconstruction and arrangement as will be more apparent from the followingdescription made in accordance with the accompanying drawing in which:

Figure 1 is a view in elevation of the lower portion of a well casingprovided with a lloat shoe and the lill-up device as provided by theinvention.

Figures 2, 3, 4, and 5 are longitudinal cross sectional views of thetill-up mechanism, which is connected in the lower portion of the wellcasing and above a float shoe, the mechanism being shown in positionsassumed during its operation as later described.

Referring to the drawing in detail, and lirst to Figure l,

`it will be seen that a well casing string 10 is illustrated as beinglowered into a well bore 12. Connected to the lower end of this wellcasing 10 is a oat shoe 14 of any conventional and reliable design.Above this oat shoe 14, at such `an interval as may be desired, is thetill-up device herein embodied as a casing collar 16 forming a part ofthe casing string 10. I

As best shown in Figure 2, the collar 16 may be threadedly or otherwiseconnected in the casing string 10 and forms a part thereof. Transverselylocated in collar 16 are ports 18. Axially mounted within collar 16 is apiston-like sleeve 20 having ports 22 adapted to be supportedin registrywith collar ports 18 by a shear screw 24. Interposed between andcircumscribing said ports 18 and 22 are sealing means exampled by Orings 19. Within sleeve 20 and adapted to close sleeve ports 22 arecheck valves 26 which have yieldable means, exampled by coil springs 27,to permit iluid ow through said ports 18 and 22 only upon application ofa positive pressure applied outside the collar 16. Valves 26 and springs27 are supported within collar 20 from a diametral web, shown in sectionbetween said valves, on which said valves and springs are laterallysupported. Thus, each valve 26 in combination with sleeve port Z2,functions as a spring loaded check valve, permitting uid llow throughport 22 only from outside said sleeve. Itis then seen that the valves Z6may be repeatedly opened and closed upon discrete applications ofpositive pressure from outside collar 16, as occurs in operation.Forming a piston-like head on the lower end and transverseto the axis ofsleeve Ztl is a partition 28. Closing a large ilow passage 3l) of thepartition 23 is a rupture diaphragm 32, said diaphragm being so arrangedas to block all axial flow through the casing 10 and sleeve 20 exceptingthat provided by relief passage 34, also provided in the sleevepartition 28.

As best shown in Figures 3 and 4, a retaining ring 36 is provided aboutsleeve 20 and confined by the inner wall of collar 16. At such time assleeve 20 is moved downwardly, said retaining ring 36 engages a recess38 provided in collar 16, interlinking sleeve 20 and collar 16, andpreventing further relative longitudinal move- It is to be clearlyunderstood that various structural modifications may be made and yetconform to the spirit of this invention. For example, the multipleports, check valves, and passages shown need not be multiple.` yAlso theshear screw 24, retaining ring 36, diaphragm 32 and lugs 40 and 42 areintended to be means for functions later described and may besubstituted for equivalent structures by those skilled in this art.

In the usual operational procedure the fill-up collar 16, as embodied bythis invention, may be connected in the lower portion of the casingstring and above the float shoe 14 a distance of from about twenty tosixty feet. As will be later described, the section of casing 10 foundbelow the fill-up collar 16 will normally be filled with cement afterthe cementing operation is completed.

As the casing string 10 is lowered into the well bore, the drillingfluid therein creates a hydrostatic pressure greater than the pressurewithin the casing. This pressure differential increases with well depth,and, at a level determined by the strength of the check valve springs27, fluid enters casing 10 through the collar ports 18 and sleeve ports22 as illustrated in Figure 2. Since a definite outside positivepressure is required to open check valves 26, a lower fluid level(hydrostatic head) will always be found within casing 10. As the fluidenters the sleeve 20, the section of casing 10 found below collar 16 isfilled by fluid entering through the sleeve relief passages 34.

Since the casing string 10 is assembled and lowered into the well boresection by section, some surging of the fluid within the casing will beevident as the descent of said casing is abruptly checked. It isprovided that such fluid surgesbe admitted through the sleeve reliefpassages 34 and thence down through the casing and out the check valveprovided in float shoe 14. Sufficient flow area is provided in thesleeve relief passages 34 to dissipate such surges without there being asufhcient differential pressure created to rupture the full flow passagediaphragm 32.

It is of note that certain advantages reside in filling the casingstring by means of this invention as herein embodied. One such advantageis that the impact or ramming pressures created by the descent of thecasing are removed from this device and have little or no deleteriouseffects. Another advantage is that the ports through which the fluidenters the casing are at right' angles to the normal fluid flow in thewell bore and thus any suspended cuttings or other detritus will tend tobe forced past rather than into said ports.

It is now clear that the casing 10 will fill to a predetermined distancebeneath the Well bore fluid level and such difference in level willremain relatively constant throughout the entire lowering of the casing.

As best shown in Figure 3, the casing string 10 has been lowered to itsfinal position and fluids are now pumped down through the casing 10 andout through the float shoe 14. Such fluids must pass through the sleeverelief passages 34 of collar 16 and in so doing create a pressuredifferential across the sleeve partition 28, and a downward force onsleeve 20. Resisting this downward force thus created is shear screw 24.At a predetermined force the shear screw 24 yields and sleeve 20 dropsto a lower position; whereupon the sleeve retaining ring 36 engages thecollar recess 38. The sleeve, when so engaged in this lower position, isnow supported against any further longitudinal movement. In this loweredposition of the sleeve 26, collar ports 18 and sleeve ports 22 are nolonger in registry and the collar port 18 is further sealed by theO-rings 19. Thus, after the sleeve 20 has been moved to a lowerposition, a permanent closure to fluid entry or exit is effected.

As best illustrated in Figure 4, a greater pressure differential,applied by an increased flow rate of fluids through the casing 10, iscreated across the sleeve partition 28. The flow passage diaphragm 32 ofsaidpartition 28 ruptures at this greater differential pressure, leavingthe sleeve partition flow passage 30 unobstructed for the impendingcementing operation.

The well is then cemented, the upper portion of the sleeve 20 serving asa landing stage for the cementing plugs. It is now seen that the casing10 provided between the fill-up collar 16 and the float shoe 14 is forthe purpose of retaining any cement that may have been contaminated bythe displacing fluids. A strong bond in the immediate vicinity of thefloat shoe 14 is highly desired and a bond of uncontaminated cement isthus insured.

It is of note that the sleeve 20 as illustrated and embodied herein isprovided of composite construction, having an outer shell of materialsimilar to that of the collar 16 and an inner construction of somedrillable material such as a phenolic resin. When so provided, thepreviously described supporting web may be integrally cast or molded ofthe same drillable material. While such construction does not enhance oreven affect the operation of the invention as herein described, aconsiderable advantage is attained when the casing 10 is drilled outpreparatory to completion of the well. Figure 5 best illustrates thecondition of the fill-up collar after the drilling operation.

In actual practice the springs providing the closing means for the checkvalves 10 are selected to provide a fluid level within the casing 10 ofabout eighty feet below that in the well bore 12. The previouslydescribed downward surges have been found to seldom exceed 500 p. s. i.and the shear screw 24 and sleeve partition relief passages 34 are sizedin accordance. Thus a pressure differential across the sleeve partitionof about 550 p. s. i. will shear the screw 24 and force the sleeve toits lower latched position. An increase in pressure differential toabout 650 p. s. i. will then rupture the flow passage diaphragm 32 aspreviously described.

Although only one embodiment of this invention has been shown anddescribed herein, it will be evident to those skilled in the art thatother embodiments and arrangements may be used without departing fromthe spirit of the present invention and the scope of the followingclaims.

We claim:

1. An improved devi-ce for filling a well casing which includes atubular body adapted to be connected in a well casing, a sleeve movablefrom an upper to a lower position within said body, said sleeve and saidbody having transverse ports therein positioned in registry only at saidupper position of said sleeve, a check valve controlling inflow offluids through said registered ports operable in response to apredetermined pressure differential applied across said ports fromoutside said body, a partition means in the bore of said sleeve having aplurality of orifices therethrough, a yieldable closure initiallyclosing one of said orifices, a releasable support initially holdingsaid sleeve in said upper position, and a latch adapted to retain saidsleeve in said lower position, the arrangement being such that apredetermined fluid pressure exerted through the casing moves saidsleeve from said upper position to said lower position, and a greaterpredetermined fluid pressure exerted through the casing opens saidyieldable closure.

2. An improved device connected in a well casing suitable for filling awell casing being lowered into a well bore and cemented thereincomprising, a tubular body having an axial passage therethrough and atleast one transverse port in the wall thereof, a sleeve member having anaxial passage therethrough and at least one transverse port in the wallsthereof mounted within said body and adapted to be longitudinally movedfrom a first to a second position therein, said sleeve port and saidbody port being in registry only at the first position of said sleeve, acheck valve for controlling the flow of fluid through said sleeve portinto said well casing operable responsive to a predeterrnined pressuredifferential applied across said registered ports from outsidesaid body,a partition in said sure exerted through the casing opens said yieldablediaphragm.

References Cited in the file of lthis patent UNITED STATES PATENTSMcClendon et al Apr. 25, 1939 Bridwell Nov. 21, 1944 Brown June 16, 1953Brown Dec. 28, 1954

